Suppose that you began a 1-year study of tuberculosis (TB) infection among nursing home residents in Washington State on January 1, 2021. You enrolled 500 residents in your study and checked their TB status monthly. At the start of your study on January 1, you screened all 500 residents. Upon screening, you found that 20 of the healthy residents were immigrants who were vaccinated for TB and so were not at risk. Another 30 residents already had existing cases of TB on January 1. On February 1, 5 residents developed TB. On April 1, 5 more residents developed TB. On June 1, 10 healthy residents left the nursing home and were lost to follow-up. On July 1, 10 of the residents who had existing TB on January 1 died from their disease. The study ended on December 31, 2021. Assume that once a person gets TB, they have it for the duration of the study, and assume that all remaining residents stayed healthy and were not lost to follow-up.  Answer the following questions. Each question below is worth 3 points each. You need to show your calculations to receive full points.  1) Is the nursing home residence community in Washington State a dynamic or fixed population? Briefly explain the rationale for your answer. What was the prevalence of TB in the screened community on January 1?  What was the prevalence of TB on June 30? What was the cumulative incidence of TB over the year? What was the case-fatality rate among residents with TB over the course of the year?   

Which of the following can be thought of as the average risk of getting a disease over a certain period of time?

Which type of studies typically take a snapshot of a population at a single point in time and therefore usually measure the disease prevalence in relation to the exposure prevalence?

The Streptomycin Tuberculosis Trial was one of the first instances that which of the following was used in medical research?

Which of the following accompanies randomization to ensure that key confounding variables are equally distributed between the treatment and comparison groups?

Which type of measures are the building blocks epidemiologist use to assess the effects of disease on a population?

True or False? Disease frequencies can be compared between different populations or between subgroups within a population.

The process of gaining the agreement of all eligible and willing individuals to participate in an experimental trial is referred to as which of the following?

True or False? Location of residence, such as country, state, city, or neighborhood, is one of the most common ways to define a population.

Some researchers believe that performing which of the following, a statistical procedure that pools data from many small trials, is a viable alternative to conducting large trials?